code: def test_labelfunc():
      text = dotprint(x + 2, labelfunc=srepr)
      assert "Symbol('x')" in text
      assert "Integer(2)" in text
  
file_path: sympy/sympy/printing/tests/test_dot.py
imports: from sympy.printing.dot import purestr, styleof, attrprint, dotnode, dotedges, dotprint
  from sympy.core.basic import Basic
  from sympy.core.expr import Expr
  from sympy.core.numbers import Float, Integer
  from sympy.core.singleton import S
  from sympy.core.symbol import Symbol, symbols
  from sympy.printing.repr import srepr
  from sympy.abc import x
label_desc: Use image node_id 9 for calling a global function with example usage: test_labelfunc() without return types